re #37 make UI compatible with new User controller API
Error and information messages modified - correct error messages from backend are displayed and information messages are translated
Set vacation changed to add vacation
User service uses correct end point to delete calendar
Modified api users service, fixed edit settings dialog
Re #7534 'Profile settings' component connected to the API
Re #7532 'Add vacation component' connected to the api
Re#7531 Components are guarded against invalid users
Re #7494 Components connected to API - except profile settings and add vacation components
Re#7528 Menu items are highlighted with correct default, added 404 page
Re#7527 SnackBar opens if the error occurs
Re#7527 Implemented import and export files on front end
Re #7499 User profile component initialized
Refactor service structure